Compilare: user.cpp: In function ‘int main()’: user.cpp:32: warning: statement is a reference, not call, to function ‘fclose’ user.cpp:32: warning: statement has no effect user.cpp:26: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘int euclid(int, int)’: user.cpp:19: warning: control reaches end of non-void function